Method development for Cd and Hg determination in biodiesel by electrothermal atomic absorption spectrometry with...

Area of Science:

• Analytical Chemistry
• Environmental Science
• Materials Science

Background:

• Biodiesel fuel quality requires monitoring for heavy metal contaminants like cadmium (Cd) and mercury (Hg).
• Traditional analytical methods for heavy metals in complex matrices such as biodiesel can be time-consuming and require extensive sample digestion.
• Developing rapid, reliable, and cost-effective analytical techniques is crucial for routine quality control of biofuels.

Purpose of the Study:

• To introduce a novel electrothermal atomic absorption spectrometry (ETAAS) method for the direct determination of cadmium (Cd) and mercury (Hg) in biodiesel.
• To establish an efficient sample preparation strategy using emulsions for routine analysis.
• To validate the accuracy and precision of the developed method for heavy metal quantification in biodiesel.

Main Methods:

• Sample preparation involved creating stable emulsions of biodiesel for direct analysis.
• Electrothermal atomic absorption spectrometry (ETAAS) was employed for heavy metal detection.
• Optimization of experimental conditions included emulsion characteristics, furnace programs, and matrix modifiers.
• Analyte addition method was utilized for calibration, and results were compared against microwave acid digestion.

Main Results:

• The developed ETAAS method demonstrated high accuracy and reliability for Cd and Hg determination.
• Injection repeatability was excellent, with relative standard deviations (R.S.D.) below 4.4% for Cd and 5.4% for Hg.
• Low detection limits were achieved: 0.3 μg kg⁻¹ for Cd and 10.2 μg kg⁻¹ for Hg.
• The method was successfully applied to quantify Cd and Hg in commercially sourced biodiesel samples.

Conclusions:

• The proposed emulsion-based ETAAS method provides a robust and efficient approach for routine analysis of Cd and Hg in biodiesel.
• This technique simplifies sample handling and reduces analysis time compared to conventional methods.
• The validated method ensures accurate heavy metal quantification, supporting quality control and safety assessments of biodiesel fuels.